Clear-Com Encore CS-702 Owner's manual

Brand: Clear-Com

Model: Encore CS-702

Type: Owner's manual

-i

INSTRUCTION MANUAL

CLEAR-COM ENCORE

CS-702 TWO-CHANNEL MAIN STATION

-ii

CS-702 Portable Two-Channel Main Station Instruction Manual

Part number: 810344Z Rev. 3

Legal Disclaimers

Clear-Com, the Clear-Com logo, and Clear-Com Concert are trademarks or registered trademarks of HM Electronics, Inc.

The software described in this document is furnished under a license agreement and may be used only in accordance with the

terms of the agreement.

The product described in this document is distributed under licenses restricting its use, copying, distribution, and decompilation/

reverse engineering. No part of this document may be reproduced in any form by any means without prior written authorization

of Clear-Com, an HME Company.

Clear-Com Offices are located in California, USA; Cambridge, UK; Montreal, Canada; and Beijing, China. Specific addresses

and contact information can be found on Clear-Com's corporate website:

www.clearcom.com

Americas and Asia-Pacific Headquarters

California, United States

Tel: +1.510.337.6600

Email: CustomerServ[email protected]

Europe, Middle East, and Africa Headquarters

Cambridge, United Kingdom

Tel: +44 1223 815000

Email: [email protected]

Canada Office

Quebec , Canada

Tel: +1 (450) 653-9669

China Office

Beijing Representative Office

Beijing, P.R.China

Tel: +8610 65811360 / 65815577

CS-702 TWO-CHANNEL MAIN

CONTENTS

Legal Disclaimers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-ii

Americas and Asia-Pacific Headquarters. . . . . . . . . . . . . . . . . . . . . . . 1-ii

Europe, Middle East, and Africa Headquarters . . . . . . . . . . . . . . . . . . 1-ii

Canada Office. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-ii

China Office . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-ii

OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

The Clear-Com Concept. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

Monitoring System. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

Dual-Action Talk Buttons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

Stage Announce (Paging). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

Call Signaling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

Program Input. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

Sidetone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4

Linking Channels Together . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4

Remote Mic-Kill Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4

Power Supply Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4

System Termination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4

Portability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4

Easy Interconnection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4

Easy System Expansion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4

Front Panel Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5

Rear Panel Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8

INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

Installation Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

Clear-Com Station Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

System Powering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2

Cable Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3

Portable Installation Cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3

Permanent Installation Cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4

Internal Options and Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4

Interconnection Setup. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6

Headsets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6

MAINTENANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

CS-702 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

Troubleshooting Tips . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2

CS-702 TWO-CHANNEL MAIN STATION

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3

TECHNICAL SPECIFICATIONS . . . . . . . . . . . . . . . . . . 4-1

CS-702 Two-Channel Station. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

LIMITED WARRANTY. . . . . . . . . . . . . . . . . . . . . . . . . . 5-I

Warranty Period . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-i

Technical Support. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-i

Warranty Repairs and Returns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-ii

Non-Warranty Repairs and Returns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-iii

Extended Warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-iii

Liability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-iii

CS-702 TWO-CHANNEL MAIN STATION

iii

IMPORTANT SAFETY

INSTRUCTIONS

1. Read these instructions.

2. Keep these instructions.

3. Heed all warnings.

4. Follow all instructions.

5. Do not use this apparatus near water.

6. Clean only with dry cloth.

7. Do not block any ventilation openings. Install in accordance with the

manufacturer’s instructions.

8. Do not install near any heat sources such as radiators, heat registers,

stoves, or other apparatus (including amplifiers) that produce heat.

9. Do not defeat the safety purpose of the polarized or grounding-type plug.

A polarized plug has two blades, with one wider than the other. A

grounding-type plug has two blades and a third grounding prong. The

wide blade or the third prong are provided for your safety. If the provided

plug does not fit into your outlet, consult an electrician for replacement of

the obsolete outlet.

10. Protect the power cord from being walked on or pinched particularly at

plugs, convenience receptacles, and the point where they exit from the

apparatus.

11. Only use attachments/accessories specified by the manufacturer.

12. Use only with the cart, stand, tripod, bracket, or table specified by the

manufacturer, or sold with the apparatus. When a cart is used, use caution

when moving the cart/apparatus combination to avoid injury from

tip-over.

13. Unplug this apparatus during lightning storms or when unused for long

periods of time.

14. Refer all servicing to qualified service personnel. Servicing is required

when the apparatus has been damaged in any way, such as power-supply

cord or plug is damaged, liquid has been spilled or objects have fallen into

the apparatus, the apparatus has been exposed to rain or moisture, does

not operate normally, or has been dropped.

15. WARNING: To reduce the risk of fire or electric shock, do not expose

this product to rain or moisture.

Please familiarize yourself with the safety symbols in Figure 1. When you

see these symbols on this product, they warn you of the potential danger

of electric shock if the main station is used improperly. They also refer

you to important operating and maintenance instructions in the manual.

Please read and follow

these instructions before

operating this product.

CS-702 TWO-CHANNEL MAIN STATION

Figure 1: Safety Symbols

EMC AND SAFETY

The CS-702 Two-Channel Main Station meets all relevant CE, FCC, UL,

and CSA specifications set out below:

EN55103-1 Electromagnetic compatibility. Product family standard for

audio, video, audio-visual, and entertainment lighting control apparatus

for professional use. Part 1: Emissions.

EN55103-2 Electromagnetic compatibility. Product family standard for

audio, video, audio-visual, and entertainment lighting control apparatus

for professional use. Part 2: Immunity.

UL 60065-7, CAN/CSA-C22.2 No.60065-3, IEC 60065-7 Safety

requirements.

And thereby compliance with the requirement of Electromagnetic

Compatibility Directive 2004/108/EC and Low Voltage Directive

2006/95/EC

This device complies with Part 15 of the FCC Rules. Operation is subject

to the following two conditions: (1) this device may not cause harmful

interference, and (2) this device must accept any interference received,

including interference that may cause undesired operation.

CAUTION

RISK OF ELECTRIC SHOCK

DO NOT OPEN

This symbol alerts you to the presence of uninsulated dangerous

voltage within the product's enclosure that might be of sufficient

magnitude to constitute a risk of electric shock. Do not open

the product's case.

This symbol informs you that important operating and main-

tenance instructions are included in the literature accompanying

this product.

CS-702 TWO-CHANNEL MAIN STATION

1-1

OPERATION

INTRODUCTION

Congratulations on choosing this Clear-Com product. Clear-Com was

established in 1968 and remains the market leader in providing intercoms for

entertainment, broadcast and industrial applications. The ruggedness and high

build quality of Clear-Com products defines the industry standard. In fact,

many of our original beltpacks and main stations are still in daily use around

the world.

Please read this manual completely to better understand the functions of this

product. If you encounter a situation or have a question that this manual does

not address, contact your dealer or call Clear-Com directly at the factory. Our

applications support and service people are standing by to assist you. (Refer to

Chapter 5: “Warranty” for contact information.) Thank you for selecting

Clear-Com for your communications needs.

THE CLEAR-COM CONCEPT

Clear-Com is a closed-circuit intercom system that consistently provides

high-clarity communication in both high-noise and low-noise environments.

A basic system consists of a single- or multi-channel power supply or main

station connected to various single- or multi-channel remote stations, such as

beltpacks and loudspeaker stations.

Clear-Com manufactures a wide variety of both portable and

fixed-installation units. All are compatible with each other. Clear-Com

intercom systems can also interface with other communication systems and

devices.

Clear-Com stations are interconnected with two-conductor, shielded

microphone cable, using 3-pin XLR connectors. One wire carries the DC

power from a main station or power supply to all remote stations, and the

other wire carries two-way (duplex) audio information. The shield acts as a

common ground. One termination (per channel) is needed throughout the

intercom network, and is usually located in the main station or power supply.

Clear-Com is a distributed amplifier system; each main and remote station

houses its own mic preamplifier, headset or speaker power amplifier, and

signaling circuitry. The automated headset detection circuit shuts off a

station’s mic pre-amp when the headset is disconnected, so background noise

on the line is not increased by an unused yet online station. Low-impedance

mic input lines and specially designed circuitry make Clear-Com channels

virtually immune to RFI and dimmer noise.

Clear-Com main stations, power supplies and certain remote stations each

have an auxiliary program input with its own volume control, which allows an

external audio source to be fed to the intercom system.

Clear-Com is a

closed-circuit intercom

system that consistently

provides high-clarity

communication in both

high-noise and low-noise

environments.

CS-702 TWO-CHANNEL MAIN STATION

1-2

Visual signal circuitry (call lights), a standard feature on all main and remote

stations, allows you to attract the attention of operators who have removed

their headsets.

Depending upon the type of main and remote stations selected and assuming

that enough DC power is available remote stations and headset stations can be

distributed along 1 mi. (1.67 km) of wire. Remote stations bridge the intercom

line at a very high impedance and place a minimum load on the line. The

audio level always remains constant and does not fluctuate as stations leave

and join the network.

The DC power provided by main stations and power supply units enable

remote stations to operate with minimal current while generating extremely

loud listen volumes. The higher voltage and low current keep voltage losses to

an absolute minimum in long lines.

DESCRIPTION

The CS-702 is a portable, two-channel main station with a regulated power

supply and a versatile monitoring system. It features excellent speech

intelligibility in all noise-levels. The CS-702 contains a mic preamp with a

limiter.

The CS-702 provides DC voltage and the ability to talk and listen on two

separate channels. It supports and monitors two intercom lines containing

remote headset or remote speaker stations.

Figure 1-1 CS-702 Front Panel

Figure 1-2 CS-702 Rear Panel

Headset

CS-702

2-Channel

Main Station

Call

Remote

Mic Kill

Sidetone

Prgm

Feed

Level

Program

Volume

D.C. Short

Intrpt

Pgm

Sidetone

Prgm

Feed

Level

Intrpt

Pgm

Announce

Earphone

Party LIne

Link

Volume

Talk

Ch. A

Ch. B

Channel A Channel B

Off

Program Input

Mic

Line

30V, 1.2A Continuous, 2A Peak

Off

Te rm

Relay Out

Channel

The power provided by

main stations and power

supply units enable remote

stations to operate with

minimal current while

generating extremely loud

listen volumes.

CS-702 TWO-CHANNEL MAIN STATION

1-3

MONITORING SYSTEM

The front panel of the CS-702 has one headset connector for use by the

operator. The operator monitors the intercom channels by turning up the

appropriate listen level volume controls (one for channel A, one for channel

B). Either channel may be monitored separately, or both simultaneously

(without tying the two channels together). These volume controls are always

active regardless of talk channel selection on the station.

The jack marked earphone is connected in parallel with the earphone circuit

of the headset connector. It can be used for monitoring or recording.

DUAL-ACTION TALK BUTTONS

Each channel has its own talk button which can either latch on, or operate

momentarily. Pressing the button quickly will toggle the talk function,

alternately turning it on or off. The talk button will illuminate amber when

activated and blue when not activated.

STAGE ANNOUNCE (PAGING)

The stage announce button on the front panel sends the signal from the

operator’s headset microphone to the balanced, line-level stage announce

output on the back panel.

The stage announce button also mutes the operator’s voice output to the

intercom channels. This mute function can be defeated with an internal

user-selectable jumper. The stage announce button also activates a SPDT

relay when pressed. The 1 ampere contacts can be used for any user-desired

control function (i.e. muting a local monitor speaker).

CALL SIGNALING

Visual “call signaling” attracts the attention of people who have removed their

headsets or turned off their speakers. The CS-702 front panel provides a call

button for each channel. Pressing the call button turns on the call lights at all

stations on that channel. The call is active regardless of talk status.

When a remote station sends a call signal, the call button associated with that

channel flashes red, whether or not the channel is selected.

PROGRAM INPUT

The CS-702 accepts a balanced, mic-level or line-level program input which

can be monitored in the headset. Program volume for the operator’s headset is

adjustable with the program volume knob on the front panel. The external

program is also assignable and adjustable in level to either or both channels,

and mixes with the intercom signal. The program feed can be set to be

interrupted by the talk for a particular channel.

CS-702 TWO-CHANNEL MAIN STATION

1-4

SIDETONE

The sidetone controls for each channel on the front panel allows adjustment of

the operator’s own voice as heard in the headset.

LINKING CHANNELS TOGETHER

A front panel button is provided. It allows the operator to instantly connect

channel A and channel B together for a combined intercom system consisting

of both channels.

REMOTE MIC-KILL FUNCTION

The CS-702 provides the ability to turn off any open mics on remote stations.

Momentarily pressing the RMK button will remove the DC power from both

channels clearing the talk function of all the beltpacks.

POWER SUPPLY PROTECTION

The CS-702 power supply is regulated, current-limited, and provides DC

power from an AC mains supply. The CS-702 has an automatic short-circuit

sensor to protect the system from miswired cable, shorts in the lines, or

general current overload. If a short occurs, the red LED on the front panel

marked D.C. Short illuminates. Removing the short will cause the power

supply to reset itself automatically in as little as ½ second, depending upon

whether there was a single or multiple short or overload.

SYSTEM TERMINATION

The CS-702 provides individually-selectable audio termination networks for

both channel A and channel B.

PORTABILITY

The unit is lightweight and sturdy for applications that require that it be

moved between various locations.

EASY INTERCONNECTION

The CS-702 provides three 3-pin, male XLR outputs for channel A

(connectors are wired in parallel) and three for channel B. Intercom signals

are fed from the CS-702 with standard mic cable (see next section).

EASY SYSTEM EXPANSION

The CS-702 can be connected together with other CS-702s or other

Clear-Com power supplies for multiple two-channel systems and back-up

power support.

CS-702 TWO-CHANNEL MAIN STATION

1-5

FRONT PANEL DESCRIPTION

Normal operation of the CS-702 only requires access to the front panel

controls. For intercom operation set the listen level controls for each channel

to desired level and press the talk switches when talking. The rest of this

section is a detailed description of each control.

Figure 1-3 CS-702 Front Panel

1. Talk Buttons: Each channel has its own illuminated talk button for

activating the microphone feed to a given channel. Mechanically the

pushbutton is momentary in action; however, electrically the button has

dual action (momentary or latching) depending on how the button is

pressed.

• MOMENTARY: Press and hold the talk button while speaking.

Release it when finished.

• LATCHING: Press and release the button quickly to latch the talk

function. Press and release the button again to turn off the talk

function.

• TALK INDICATION: The talk button illuminates amber when you

press it to send a talk signal, and blue when not active. When

illuminated blue, the talk button indicates that the station is receiving

power.

• CALL INDICATION: The call button will flash red when a call

signal is received on the channel.

2. Call Buttons: Each channel has its own call button. Pressing the call

button at any time will send a call signal on that channel regardless of the

activation of the talk circuit for that channel.

The call button for that channel illuminates brighly when pressed, indicat-

ing the presence of a call signal on the line.

3. Listen Level Controls: Each channel has a separate listen level control.

Listening is always on and is not controlled by any logic. To listen to a

Headset

Call

Remote

Mic Kill

Sidetone

Prgm

Feed

Level

Program

Volume

Intrpt

Pgm

Sidetone

Prgm

Feed

Level

Intrpt

Pgm

Announce

Earphone

Party LIne

Link

Volume

Talk

CS-702

2-Channel

Main Station

D.C. Short

Ch. A

Ch. B

OffOff

Channel A

Channel B

CS-702 TWO-CHANNEL MAIN STATION

1-6

channel, turn up the appropriate control. To not listen to a channel, turn

the control completely off.

4. Sidetone Controls: Each channel has a sidetone null control. This control

is used to set the amount of the microphone that is heard in the earphone

from that channel.

This control is a true hybrid null control and therefore is sensitive to

changes in line loading. For headphone use it is best to find the null for a

given channel and then rotate the control clockwise to obtain the desired

sidetone level.

If an external speaker is used providing a possible acoustic feedback path,

it will be necessary to use an almost complete null of the sidetone control.

5. Remote Mic Kill Buttons: It sometimes becomes desirable in an

intercom system to turn off all open microphones in a system.

Pressing and holding the RMK button for several seconds will reset all

open microphones at all beltpacks on both channels.

Caution: RMK CANNOT be used if power for a channel is derived from

some place other than the local station. The RMK action

momentarily shorts the power line of the affected channel. RMK

only works from a single main station system.

6. Program Enable Switches: The CS-702 has the ability to feed an

external program signal to either of the two channels independently. The

program enable switch allows the program to be turned on, off, or on with

interrupt.

•In the on position, the program is fed to the channel under all

conditions.

•In the off position, the program is not fed to the channel.

•In the int position, the program is fed except when a talk is activated

to the channel. This program interrupt or IFB function can be used

for talent cuing and dressing room show monitor applications.

7. Program Feed Level Controls: Each channel has a program feed level

control that sets the amount of program being sent to that channel when

the program is activated.

8. Headset Connector: The headset connector is located on the front panel.

All Clear-Com headsets are recommended for use with the CS-702. The

following is a description of the characteristics of a suitable headset:

• Mic Type --- Dynamic, see technical specifications for details

• Headphone --- Dynamic, see technical specifications for details

The wiring of the headset is to be as follows:

• Pin 1 --- Mic common

• Pin 2 --- Mic hot

• Pin 3 --- Headphone common

• Pin 4 --- Headphone hot

CS-702 TWO-CHANNEL MAIN STATION

1-7

The mic and headphone wiring in the headset cord must be individually

shielded. Do not connect pins #1 and #3 together. Headset extension

cords or headset “Y” cables are not recommended because they will

increase crosstalk between channels.

9. Earphone Jack: The jack marked earphone provides an output intended

to drive an extra earphone. This output is capable of driving a headphone

or loudspeaker.

10. Party Line Link Switch: This switch marked Party Line Link on the

front of the unit allows the operator to “combine” channels A and B so

that all stations can talk to each other. (Normally channels A and B are

totally isolated and stations on one channel cannot talk to stations on the

other channel.) When in the Party Line Link operating mode, only the

channel A controls operate. The channel B controls have no effect.

Note: When the switch is in the Party Line Link position, the channels

do not actually “combine.” What really happens is that the three

“B” channel connectors are simply internally disconnected from

the “B” circuitry and connected to the “A” channel circuitry,

putting all stations on the channel “A” party line. This maintains

all the correct line and station terminations.

Caution: The link function will work properly at the main station that is

providing the “line terminations” for the system. If there is

more than one main station in the system equipped with a

“link” switch, DO NOT ATTEMPT TO USE THE “LINK”

SWITCH ON THE STATIONS THAT ARE NOT

PROVIDING THE LINE TERMINATION. Both double-line

termination and station un-termination will result, causing

significant sidetone mis-adjustments and possible feedback and

oscillation.

11. Program Volume Control: The program volume control sets the amount

of the program signal heard directly in the headphone. This control only

affects what is heard in the headphone and does not affect program feed

to the intercom lines.

12. Announce Button: The announce button allows the operator to instantly

use the microphone input to directly talk to a system external to the

intercom such as a paging speaker/amplifier in another room. A dry set of

relay contacts on the rear panel is also available that can be used to

activate external switching as needed when the announce button is

pressed.

Pressing the announce button momentarily disables any active talks.

Active talk circuits will be restored when the button is released. The talk

muting action can be defeated if desired by moving an internal jumper

(refer to the section “Internal Options and Adjustments”).

13. Power Supply LEDs:

• NORMAL OPERATION: The talk buttons illuminate blue when the

station is receiving power.

• OVERLOAD AND SHORT CONDITIONS: A red D.C. Short light

indicates that an overload or short condition exists.

CS-702 TWO-CHANNEL MAIN STATION

1-8

Lowering an excess load or removing a short will allow the automatic

reset circuit to attempt to reset the power supply, to restore normal opera-

tion to the power supply without operator intervention.

REAR PANEL DESCRIPTION

Figure 1-4 CS-702 Rear Panel

1. Power Switch: The AC power switch is located on the bottom left corner

of the rear panel.

2. Power Connector: Just above the power switch is an EIA power

receptacle for AC power input.

3. Intercom Line Connectors: There are two sets of three XLR-3M

intercom connectors for both channel outputs. Standard Clear-Com

wiring is as follows:

Pin #1 --- Ground

Pin #2 --- Power

Pin #3 --- Intercom audio

4. Termination Switches: Each intercom channel is provided with a

termination switch allowing easy termination of the intercom line. The

switch is provided in case there are multiple main stations connected to

the intercom line.

Caution: For proper operation it is imperative that one and only one

termination be present on a Clear-Com line. Clear-Com line

drivers depend on a known load value for proper operation.

5. Announce Output Connector: The announce output is an XLR-3M. The

output is transformer isolated. Wiring is as follows:

Pin #1 --- Ground

Pin #2 --- -Audio

Pin #3 --- +Audio

Off

Te rm

3 7

Program Input

Mic

Line

Relay Out

30V, 1.2A Continuous, 2A Peak

Channel

CS-702 TWO-CHANNEL MAIN STATION

1-9

6. Announce Relay Contact Terminals: The announce relay contacts are

available on a 1/4” jack. The contact description is as follows:

Tip--- C --- Common

Ring--- N/C --- Normally Closed Contact

Sleeve--- N/O --- Normally Open Contact

7. Program Input Connector: The program input is an XLR-3F. It is an

electronically balanced (differential) input. Wiring is as follows:

Pin #1 --- Ground

Pin #2 --- -Audio

Pin #3 --- +Audio

8. Program Gain Switch: The program input gain switch is located next to

the program input connector. In the mic position the input will accept a

low-impedance dynamic microphone and gives a gain of 41dB from input

to the Party Line.

In the line position the input presents a balanced high impedance and

gives a -16dB gain from input to Party Line.

Caution: These servicing instructions are for use by qualified service

personnel only. To avoid electric shock, do not perform any

servicing other than that contained in the operating

instructions unless you are qualified to do so.

CS-702 TWO-CHANNEL MAIN STATION

1-10

CS-702 TWO-CHANNEL MAIN STATION

2-1

INSTALLATION

INSTALLATION OVERVIEW

The CS-702 is a combination of a very versatile intercom station and a system

power supply. Installations can vary depending on what features are used. The

fundamental concept of the Clear-Com party-line intercom is that all stations

provide high impedance current sourced signals into a single common system

termination.

The high DC resistance allows a call voltage to be placed on the line without

drawing too much current. The DC source for this call signal is also a current

source thereby providing a high impedance and not affecting the audio signal.

The receive or “listen” section of stations contains a hybrid null circuit that

attempts to reject (null) any talk signal being sent by that station on that

channel. The hybrid null circuit depends on a known impedance on the

intercom line to accomplish this. Variations in impedance on the line upset the

null.

Clear-Com main and some remote stations provide switch-selectable

termination networks on all intercom output lines. It is up to the user to

determine where the termination will be provided. An unterminated line will

cause excessive levels, possible oscillation of line drivers, and severe

unbalance of hybrid null networks. A double- or multiple-terminated line will

cause low levels and severe unbalance of hybrid null circuits.

Caution: All Clear-Com intercom lines must be terminated. Care must be

taken NOT to fail to terminate or to “double-terminate” a line. All

unused intercom inputs must be terminated to keep the line drive

circuits stable.

CLEAR-COM STATION TYPES

Clear-Com party-line intercom stations all fall into one of four distinct

categories that relate to system powering and termination. The four types are

as follows:

A. MAIN STATION:

• Supplies system power for external stations.

• Provides switch-selectable terminations.

B. MASTER STATION:

• Contains a power supply just for itself.

• Provides switch selectable line terminations.

C. REMOTE STATION:

CS-702 TWO-CHANNEL MAIN STATION

2-2

• No power supply. Derives power from the intercom line.

• May or may not have terminations.

D. POWER SUPPLY:

• Supplies system power for external stations.

• Provides switch-selectable terminations.

SYSTEM POWERING

Typical Clear-Com systems consist of a main station and multiple remote

stations. The remote stations are powered from the main station through the

intercom cable (Figure 2-5).

Figure 2-5 Typical Single Power Source System

Clear-Com power supplies can be paralleled to increase the number of remote

stations that can be operated in a system (Figure 2-6). The termination

switches in the second power source would need to be in the off position.

Note: The RMK function will not work on a system that has two or more

power supplies.

Figure 2-6 System With Multiple Power Sources

CS-702 TWO-CHANNEL MAIN STATION

2-3

CABLE CONSIDERATIONS

The Clear-Com intercom line is intended to run on a shielded twisted pair of

cable per channel of intercom. One conductor carries full duplex (two-way)

audio, the other conductor carries the DC power for remote stations. The

shield is used for ground return for audio and power. When choosing

interconnect cable, keep the following considerations in mind:

1. DC resistance of the ground or common conductor affects crosstalk. For

runs longer than 100 ft. (30.5 m) do not use wire smaller than 20 gauge.

The total resistance of the ground return (the combined parallel sum of all

shields to a location) to any point in the system should be under 1.5

2. The capacitance of the interconnect cable affects system frequency

response and sidetone stability. Total capacitance should not be greater

than 0.25 uF (capacitance between conductor and shield) equivalent to an

intercom system containing 5,000 ft. (1525 m) of cable at 50 pF per ft.

(0.305 m).

Portable Installation Cable

Typical cable for portable system interconnections is flexible, two-conductor,

shielded microphone cable. For runs less than 500 ft. (152.5 m) a cable made

of 24-gauge wire is acceptable. For runs longer than 500 ft. (152.5 m) use a

20-gauge cable or larger.

Portable remote stations such as beltpacks have a pair of input and output

connectors; when installing a system that includes these, they can be

daisy-chained or loop-through connected along one interconnect path.

Daisy-chaining and line-splitting decreases the amount of cable required and

simplify the installation.

CS-702 TWO-CHANNEL MAIN STATION

2-4

Permanent Installation Cable

Vinyl-jacketed shielded pair is the cable of choice for permanent installations.

Use a low-capacitance 20-gauge wire for short runs (under 500 ft. [152.5 m])

and 18-gauge cable for runs greater than 500 ft. (152.5 m). Placing the cable

in conduit is recommended but not necessary.

Multi-pair cable that is individually shielded is acceptable for use in

multi-channel systems. For cross-talk considerations, the shields must be tied

together on both ends of the cable to produce the lowest possible DC path for

ground return.

INTERNAL OPTIONS AND ADJUSTMENTS

To access the internal options and adjustments, you must remove the station’s

cover to gain access to the internal circuit board.

Before removing the station’s cover ensure the power to the station is

disconnected.

Remove the screws on either side of the station. Remove the four screws on

the top of the station. Remove the cover.

Note: These adjustments should only be carried out by qualified service

personnel.

Figure 2-7 Location of Jumpers and Adjustments on PCB

1 JP-1 and JP-2 Line Length Selection Jumpers: Jumpers JP-1 and JP-2

allow the optimization of the hybrid null circuitry for excessive intercom

cable lengths. JP-1 is for channel A and JP-2 is for channel B.

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Clear-Com Encore CS-702 Owner's manual

Clear-Com Encore CS-702 Owner's manual

Clear-Com Encore CS-702 Owner's manual

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